The results of a controlled horticulture lighting study conducted by the US National Science Foundation (NSF)-funded Center for Lighting Enabled Systems and Applications (LESA) at Rensselaer Polytechnic Institute (RPI) in Troy, NY, USA have been released. Utilizing a variety of commercial LEDs, the study compared the effectiveness of different LEDs on the growth of red lettuce Rouxai. The best combined yield and antioxidant concentrations in the lettuce was observed using LUXEON SunPlus Series LEDs made by LED maker Lumileds of San Jose, CA, USA.

“Comparing the growth results using different combinations of LEDs shows that the spectra that performed best for yield (fresh weight), anthocyanin and chlorophyll concentrations were the LUXEON SunPlus Lime + Purple and Green + Purple LEDs from Lumileds,” says LESA’s Dr Tessa Pocock, an expert on light and plant physiology. “Green light is necessary for crop growth and the specific wavelengths within the green region matters.” This work is also part of the Greenhouse Lighting and Systems Engineering (GLASE) Consortium operated by LESA and Cornell University and funded by the New York State Energy Research and Development Authority (NYSERDA) that is examining the most effective way to add green light to horticultural fixtures.

“Growers today are experimenting with various LEDs to arrive at the best color combinations for their crops,” notes LUXEON SunPlus Series product line director Jennifer Holland. “The LESA study indicates that such experimentation is paying off because a common, nutrient-rich crop can be produced with excellent yield,” she adds. The study demonstrated that a light spectrum like the combination of LUXEON SunPlus Lime and Purple, which contains a certain ratio of royal blue, green, deep red and far red components, is beneficial to growth optimization.